She bought it through the so-called Honest Used Car Dealers Association.

Advanced English Dictionary

+adjective1[only before noun] used to show that you do not think that the word or phrase that is being used to describe sb/sth is appropriate: the opinion of a so-called 'expert' + How have these so-called improvements helped the local community?2[usually before noun] used to introduce the word that people usually use to describe sth: artists from the so-called 'School of London'